Trolley duct



Ap 1954 J. A. HERRMANN TROLLEY DUCT 5 Sheets-Sheet 1 Filed May 25, 1950 INVENTOR fi fl/rerrmdrzrr April 13, 1954 J. A. HERRMANN 2,675,434

TROLLEY DUCT Filed May 25, 1950 3 Sheets-Sheet 2 INVENTOR J25 f1 flerrrrfdnfl.

J. A. HERRMANN TROLLEY DUCT April 13, 1954 3 Sheets-Sheet 3 Filed May 25, 1950 INVENTOR fi /7/rrma777z Patented Apr. 13, 1954 UNITED STATES PATENT OFFICE 2375,4341, T F' U J'ohh A. Hermann; Grosse some Farms, Mia. assignonto BullDog Electric Products 00., Detroit, Mich.,'ia: corporation of West Virginia Application 25;1950, Serial No. 164,247

2 Claims." (01.191423) This invention relates to electrical 'distr ibution systems and more particularly concerns the duct portion of a trolleyductsystem. 4 i H 1} particular feature of the present invention is in: the provision of a duct for a trolley duct type of electrical distribution system which may be economically manufactured, which comprises a minimum number ofparts, and which maybe easily maintained in operating condition.

'A" further ieaturej lies in the provision of a. duct, for a system of the'character described, in the form of "an open bottom channel having transverse insulators, at longitudinally spaced points which support the longitudinally ,exteiid. ing bus bars. 'These'bus bars are shielded by" insulation material in strip" or sheet form or the like, surrounding the'bus bars on all sides except the bottom side facing the open side of thechanneL; The shielding strip is formed to restrict access to the open or exposed surfaces of the busbar. Such construction, then, is characterized by the use of an, open sided channel described in connection .with' the appended draws ings wherein:

Fig. 1 is a perspective view of a unit length of trolley duct.

Fig. 2 is a transverse section view on line 22 of Fig. 1.

Fig. 3. is a perspective view 'of an insulator support for bus bars per se. 7

Fig. 4 isaview illustrating the-crosssectionof trolley duct at an insulator support for bus bars.

Fig. 5 is a perspective view showing means for coupling bus bars end to end where unit lengths of trolley duct join end to end.

Fig. 6 is a perspective view of an end closer for the trolley duct.

A trolley duct normally includes unit lengths, joined end to end to become an electrical distribution system. One such unit length is shown in Figs. 1-4.

H p g .i features and objects of the" Such unit length includes a casing which may be sheet metal made up of two halves, 40-42 which are arranged to provide an open bottom 'This joins the casingsendto end.

, 2 channel. Each half is of ogee form and has. a central flange 43. Flanges 43, 43 may be welded or riveted together, as by rivets M passing through rivet holes 45, and some of which may be utilized to receive bolts enabling the duct to be connected to vertical hangers, if desired. In a unit length, each half will project beyond the otherhalf at one of the two ends of the unit length to provide a scarf lap, end-to-end joining means for unit lengths, the joiningbeing effected by passing rivets-or bolts thru meeting holes 45 of the meeting flanges 43.

In assembling thecasing halves 40-42 toform a..'channel, the halves of the casing are so. positioned that eaclrprojects beyond the other at one end, as illustrated in Fig.1.v In this way, a

unit length .of trolleyductis fabricated andis ready to be joined end to end with additional unit lengths to -form a complete run of duct. When two unit lengths are joined end toend, the scarf lapconstruction enables a casing half 40 of one unit length to be joined to a casing half 42 of the next adjacent unit length by the use of rivets orbolts passed throughaligning holes 45 in the flanges-43 ofthe two unit lengths.

Within the casing-end. secured thereto by lugs lfl ben't inwardlyfrom the vertical side flanges I 49 of. the halves'40-4'2, and best visualized-in Fig. 4, are longitudinally spaced'transverse cleats or blocks 50 of insulation, having grooves-5i in their sides, defining ribs 52 for receiving the lugs-48 of. thecasing.

IRunning from end to end of each unit length and formed with ridges 54- interloclcing into the sockets 56 of the supporting cleats or blocks 50 is. an insulation shield or liner 58 of thin flexible insulation material rigid enough tobe shapesustaining and self-supporting but flexible enough to be bent on longitudinal edges of its ridges 54 to permit U -s'h'aped bus bars tear the form shown in Fig. 4 to be snapped into the grooves of ridges 54 and to be held there by shoulders 62 of such grooves of the insulation liner 58.

The assembly of a unit length is eiiected in the following manner. Three bus bars 60 are snapped into the grooves 54 of the liner 58 when the latter is opened up laterally to a slight extent to permit the bus bars to be disposed in the grooves 54. The bus bars and the liner then form a. sub-assembly onto which may be slid, from an end, the required number of the insulator blocks or cleats 50. These are positioned on the sub-assembly 58-450 approximately in the proper locations to correspond with the lugs 48 of the casing halves 40--42. The casing is then separately applied to the sub-assembly of the liner 58, the bus bars 60, and the cleats 50, with the lugs 48 aligning with the grooves 5| of the cleats and with the holes 45 of the two halves aligning and then the halves of the casing may be fastened together.

The mechanical end to end coupling of the bus,

bars of the two unit adjacent lengths (mentioned above) is eilected by the use of coupling bars I0 having ends in each of two end to end abut-. ting bus bars 60. The end of each bus bar 60 is formed with an inwardly bent flange portion I2 overlying the coupling bar 70 and assist,- ing in holding itself and the coupling bar in assembly. Each coupling pin is longitudinallyslotted as shown at 14 and is tensioned initially to spread laterally and be compressed when the bus bars are coupled end to end. In this way, the coupling is effected with considerable spring pressure which assists in maintaining mechanical connection and electrical contact between busv bars joined end to end.

The positive alignment of the bus bars end to end effected through the coupling bar is of importance in a trolley duct, since the bus bars,

provide tracks for collectors on the trolleys. The positive: alignment of the bus bars enables the,

trolley to. move smoothly.

The positive. alignment of the bus bars end to end, effected by the coupling bars 70, also main,

tains positive alignment, of the insulation liners 58 as these are disposed in end abutting relation.

Fig. 6,v shows an end closer unit which may be applied as a unit to the. open end of any unit length of trolley duct. The end closer is a sheet metal box. including abottom I20, an end wall I22, and a half side, section I24. which complements the projecting end of the casing half 40 shown at the left end of Fig. 1. Thus it has a flange I26 with rivet, holes I28. to complement the flange 43 and the holes 45. of the. casing. half 40, at. the left end of Fig. 1.

Across, the open end of the, end closer at the bottom is a. fibre bumper bar I30v which forms a stop for the movement of trolleys.

The duct hereof, includesan open bottom channel in. which at. longitudinally, spaced points are they insulator supportsor blocks 50 which support longitudinally extending bus bars, to. and that these. bus bars. though exposed to, the open botm. of the. channel, are nevertheless suitably shielded by the insulator strip. 58. so that the under urfaces of. the bus. ars are properl shielded gainst. improper on t.

Whil h d ct. h r of. is primarily suited for use with movable trolley type current collectors.

stationary outlets may also be employed with the duct disclosed.

I claim:

1. In a, rolley duct. the combination of a plu- .q s rality of electrically conducting rails. and an insulating liner of sheet insulation having continuous longitudinally extending ridges formed of the sheet itself to define open grooves in which the rails are disposed, spaced insulator cleats, each having sockets for receiving the ridges of the liner, and an open bottom casing comprising two longitudinally flanged halves of ogee form containing said cleats laterally between them, fastening means for joining said halves thru their cooperating longitudinal flanges, and means on the outer flanges of the halves for retaining said cleats against longitudinal displacement and from downward movement relative to said casing, said means, comprising lugs on the outer vertical flanges. of said halves cooperating with ribs on the outer vertical surfaces of said cleats each half of the casing projecting beyond the other half at an end of the trolley duct to provide scarf lap joining means for joining casings end to end, these being joined by connection means passing through the central flanges of the central halves, an end closer for such casing comprising a bottom, an end, and a half side and top of ogee form, the, other side and top half of the end closer being open to receive the projecting end of the casing half, the end closer having a central top flange meeting the, central top flange of the projecting casing half to enable the end closer to be secured to the projecting casing half by means passing laterally through said meeting top flanges.

2. A trolley duct comprising an open bottom casing, insulating supports, disposed at spaced in tervals in said casing, said insulating supports including rectangular openings having reduced sections opening towards the bottom of said casing, a longitudinally and laterally continuous combined guiding and supporting insulating strip secured to said supports and formed to the contour of the bottom surface of, said insulating block including the surface of said rectangular openings and said reduced sections, and a flexible bus bar fully held within each of the rectangular openings and interlocked with said insulating supports and said insulating strip.

References Cited in the file of this patent UNITED STATES PATENTS Number Name. Date 1,398,005 Colabrese Nov. 22, 1921 2,048,378 Hofner July 21, 1936 2,090,725 Frank'et a1. Aug. 24, 1937 2,096,579. Frank et a1 Oct. 19, 1937 2,120,251 Johnson June 14, 1938 2,144,872: Cruser Jan. 24, 1.939 2,170,300 Frank Aug. 22, 1939 2,304,924 J acksonv et a1 Dec. 15, 1942 2,322,799 Frank June 29, 1943 2,358,116: Wehr Sept. 12, 19.44 2,481,194 Bubb etal., Sept. 6., 1949 2,495,526 King Jan. 24, 1950 

